Guard device



F. C. MASON.

Gum) DEVICE. APPLICATION FILED AUG.29, 19H.

Patented Aug. 26, 1919.

flan/P 0. Mason 7 Q4113 7 1:44

FRANK C. MASON, OF LOS ANGELES, CALIFORNIA.

GUARD DEVICE.

Specification of Letters Patent.

Patented Aug. 26, 1919.

Application filed August 29, 1917. Serial No. 188,861.

To all whom it may concern:

Be it known that I, FRANK C. MASON, a citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented a new and useful Guard Device, of which the following is a specification.

This invention relates to a guard means for protecting the locks of safes or vaults, or generally for the protection of any lock or catch which controls access to any inelosure, so as to prevent tampering with such lock or catch by an unauthorized person.

My invention comprises a device in the nature of a cover or shield, which is adapted to extend over and cover the operating means for the lock or catch, and is provided with alarm or signal controlling means operated on mutilation or displacement of said device, so that any attempt to remove or mutilate the device for the purpose of obtaining access to the lock, etc., will result in an alarm or signal, and will either lead to ap prehension of the person attempting the forcible entry, or will cause such person to desist from such attempt.

The accompanying drawings illustrate embodiments of my invention, and referring thereto:

Figure 1 is a. vertical section of the device in position on a safe lock knob.

Fig. 2 is a front elevation thereof, partly broken away, the circuit connections for the electric alarm or signal means being shown diagrammatically.

Fig. 3 is a rear elevation of the device, partly broken away.

Fig. 4 is a vertical section of a modified form of the invention, and

Fig. 5 is a front elevation thereof, partly broken away. I

In Figs. 1 to 3, the device is shown as a hollow cover or shield member 1, preferably of sheet metal, and having an inner shell 2 mounted within the same by insulating blocks 3, of any suitable insulating material and fastened to the inner shell and the outer member 1 by any suitable means. The outer and inner members 1 and 2 are preferably dome shaped or otherwise formed so as to provide a space 4 within the inner shell 2 adapted to receive the handle or thumb knob of the lock to be guarded.

The device is adapted for attachment to a safe or vault door, indicated at 35 in Fig. 1, or other closure means for a stationary inclosure to be guarded, and is preferably provided with means for securing it to said part by engagement with the handle, knob or thumb piece 36 for the lock of such closure. For example, as shown in Figs. 1 to 3, an arm 5 may extend from the cover device into the interior space 4, said arm having suitable means, such as key hole slot 7, adapted to engage the knob or handle which is covered by the device. A suitable handle 8 may also be provided for the cover device, to facilitate its application to the part to be protected. Said device may have a pad 9 on its rim to provide a cushion bearing against the door 10, or other part against which the device was placed and said pad is preferably provided with alarm circuit controlling devices, consisting, for example, of spring contacts 10, on member 2 adapted to make contact with contacts 11 on insulating blocks 3, said contacts 11 being connected by wires 16 to the cover member 1, and said spring contacts 10 being nor mally held away from contacts 11 when the cover is in position for use, by pins 23 on said spring contacts, said pins pressing against pad 9 so that when the pad is held tightly against the door or object it will engage the pins so as to hold spring contacts 10 away from contacts 11 and thereby maintain the alarm circuit in open condition.

I may use any suitable alarm or signal devices, either audible or visual, controlled by the guard means above described, in any suitable manner. Thus as shown in Fig. 2, the two metallic members 1 and 2 may be connected to wires 18 and 19, of an alarm bell circuit, including said wire 13, bell 15, wire 17 battery 18, wire 19 and parts 2 and 1. For further protection, a closed circuit may be provided, leading from battery 18 through wire 19 to the junction 20 with wire 14, (said junction being within the cover device) and from said junction by wire 14 to a relay 22, from which a wire 21 leads to a relay 24 connected by wire 25 to bat tery wire 17. A wire 26 leads from battery wire 19, and is connected to a back contact 28 of relay 24 and to a front contact 29 of relay 22, said relays being so adjusted, that the armature 30 of relay 24 will be normally held from its back contact by the current from battery 18, but said current will be insufficient to draw armature 31 of relay 22 against its front contact. The three wires 19, 14 and 13 are insulated and twisted together in the manner of the usual triple wire flexible cord.

, The operation is as follows: The cover device is applied to the door or other part 35 to be protected, the wider portion of the key hole slot 8 being passed over the knob 36 of the lock, and the device being then pushed down and back so that the narrow part of the key hole slot engages back of the knob and holds the device in place, with the pad engaging the door so that the circuit closing springs are held in open position. If it be attempted to remove the device bodily from the door, the consequent release of pressure on pad 9 will allow spring contacts 10 to close on contacts 11, with the result that the normally open circuit above described is closed, current passing from battery 18 through wire 19, to the member 2, contacts 10 and 11, member 1, wire 13, bell 15 and wire 17 back to said battery. The ringing of the bell by this current will generally lead to discontinuance of the attempt to open the safe, and by giving warning of the attempt, will aid in prevention of the act, or the detection of the person attempting the same. If such person attempts to gain access to the lock knob or thumb piece by cutting away the cover members 1 and 2, the unavoidable insertion of a metal tool in contact with both of these members, will lead to closure of connection between them, and the bell Will be rung as above described. The pro tection of the open circuit by the closed circuit above described prevents tampering with the open circuit in well known manner, the relay 24 closing the normally open alarm circuit when either of the open circuit wires leading to the guard device is severed, and the relay 22 closing the normally open alarm circuit if it be attempted to hold the relay open by substitution of another battery, in case such substitute battery is of greater strength than battery 18; while on the other hand if such substitute battery is of less strength than battery 18, relay 24 will close the alarm circuit.

Any other suitable means may be provided for holding the device in position on the part to be protected. For example, as shown in Fig. 1, the handle 40 of the cover device 1, may be formed as a nut screwing on a shank 41 extending through said cover device and provided with a hook 43 that can be engaged over and back of the knob of V the lock and can then be drawn forward against the knob by screwing up the handle 40, until the cover device is held tight against the door or other part to which it is to be attached, the operation of handle 40 serving to simultaneously tighten the engagement of the hook with the knob of the lock and the engagement of the cover with the door. In each of the above cases, the cover device is provided with inner and outer walls, insulated from each other and wvith circuit closing devices adapted to be held open by the pressure against the part to be protected, so that any displacement or cutting of the device, in order to get access to such part, will result in an alarm.

The above described guard device may be used for protection of other than lock means. For example, it may be used to guard the controlling switch of an automobile, the door being in that case supported on the dashboard in any suitable manner so as to cover said switch, or it may be simply placed over a horizontally extending part and may be held in place by gravity to guard an object beneath it.

It will be understood that the term alarm as here used includes visual as well as audible alarmdevices.

A switch 33 is provided in the open clrcuit connection to disable the alarm circuit when the device is not in use, the switch being suitably located or guarded to prevent tampering therewith.

If a person should attempt to prevent operation of the circuit-closing contacts of the device by slipping a thin plate between the device and the door to be guarded, this will either slightly raise the device from the door, resulting in alarm as above described, or it will slightly raise the pins 23, and in order to guard against this contingency, the contacts 11 may have portions 11 extending over the spring contacts 10, so as to make contact therewith under these conditions. The spring contacts 10 press on the pad 9 with considerable pressure, so that if a person tampering with the device shifts it on the door considerably, the pins are apt to work their way into the pad sufficiently to cause the spring contact to make contact with the fixed contacts 11. In some cases however, the pad may be omitted, as it is mainly for the purpose of protecting the door or safe parts from marring by contact with the device.

The outer member '1 of the cover device is connected to the door 35 by the metallic fastening means '5 or 43 so that insertion of a metal tool under the cover, such as would cause connection between the inner member 2 and the door, would close the alarm circuit.

What I claim is:.

1. A guard device for protecting a door lock having a projecting operating means, said guard device comprising a hollow cover adapted to extend over the lock and provided with a rim for engaging with the face of the door, a member on said cover for detachably engaging said projecting operating means of said lock to hold the cover in place, and alarm circuit controlling means on said rim adapted to be held out of operative position by engagement of the rim with the door.

2. A guard device for protecting a door lock, comprising a hollow cover adapted to extend over the lock and having a rim adapted to engage the door, a member movably mounted on said cover for detachably engaging a part of said lock to hold the cover in place, and a circuit controlling means on said rim adapted to be controlled by the pressure of the rim on the face of the door.

3. A guard device for a door lock, comprising a hollow cover adapted to extend over the lock and having a rim adapted to engage the door, a hook member movably mounted within the cover for detachably engaging the handle of the lock to hold the cover in position, said hook member having a handle portion extending outside of the cover for operation thereof, and a circuit closer on the rim of said cover adapted to be held out of operation by engagement of said rim with the door.

4. A guard device for a door lock, comprising a hollow cover for the lock, having a rim portion adapted to engage the door, a circuit closer mounted on said rim and spring operated to move to closed position and normally held out of operation by pressure on the door, and means movably mounted on said cover for engaging a part of the lock to hold the cover against the door and provided with operating means for tightening its engagement with said part of the lock and the engagement of the cover with the door.

5. A guard device for a door lock, comprising a hollow cover for the lock, having a circuit closer normally held out of operation by pressure of the cover against the door, a hook Within the cover for engaging a part of the lock, to hold the cover against the door, said hook having a screw shank, and a handle outside of the cover and screwing on said shank to draw the hook into tight engagement with said part of the lock and simultaneously force the cover into tight engagement with the door.

In testimony whereof I have hereunto set my hand, at Los Angeles, California, this 22nd day of August 1917.

111mm; 0. MASON.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

